A method for recovering nickel from low-iron high-magnesium laterite nickel ore tailings

Abstract

The application belongs to the technical field of nickel resource recovery, and relates to a method for recovering nickel from low-iron high-magnesium type laterite nickel ore tailings, in particular to a method for recovering nickel from low-iron high-magnesium type laterite nickel ore tailings by using solid waste generated in industrial production of sodium sulfide as an additive. The method aims to convert waste residues and solid waste generated in the production process of sodium sulfide into useful additives for recovering nickel from low-iron high-magnesium type laterite nickel ore tailings.

Description

Technical Field

[0001] This invention belongs to the field of nickel resource recovery technology, and relates to a method for recovering nickel from tailings of low-iron, high-magnesium laterite nickel ore, and particularly to a method for recovering nickel from tailings of low-iron, high-magnesium laterite nickel ore by using solid waste generated from the industrial production of sodium sulfide as an additive. Background Technology

[0002] Nickel plays a crucial role in modern industry, particularly in stainless steel production, where it accounts for 71% of total consumption. The rise of the new energy industry is unstoppable, and the application of nickel sulfate in new energy batteries is rapidly increasing. This poses a significant challenge to China, a country relatively lacking in nickel resources. my country holds only 3% of global nickel reserves, yet its dependence on imports is as high as 85%. Currently, the world's exploitable nickel ore mainly comes from sulfide nickel ore and laterite nickel ore, with laterite nickel ore accounting for 60% of total nickel resources. The deposit structure of laterite nickel ore typically includes a limonite layer, a transition layer, and a humus layer. The limonite layer is rich in iron and cobalt, while its nickel, silicon, and magnesium content is relatively low, making it suitable for hydrometallurgical processing. The low-iron, high-magnesium laterite nickel ore in the transition layer has relatively high iron, silicon, nickel, and magnesium content, requiring extraction using either hydrometallurgical or pyrometallurgical processes depending on the specific circumstances. Lateritic nickel ore from humus layers is characterized by low iron and cobalt content and high silicon, magnesium, and nickel content, making it suitable for pyrometallurgical smelting to produce high-grade nickel and iron. During the pyrometallurgical processing of low-iron, high-magnesium lateritic nickel ore, tailings with a Ni content of 0.1% to 1.4% may be generated in the experimental stage. With the continuous growth of nickel consumption and the shortage of resource security and production supply, the future contradiction between nickel resource supply and demand will become more prominent. The treatment of lateritic nickel ore tailings and the effective recovery of nickel have become urgent problems to be solved in the mining industry.

[0003] Sodium sulfide (Na2S) production is an important process widely used in multiple industrial sectors. Sodium sulfide is mainly used in leather depilation in the leather industry, wastewater treatment, pulp and paper production, and metal extraction. The production of sodium sulfide typically involves a reaction with sodium carbonate, using sulfuric acid as a catalyst. This process generates various solid wastes, including sulfate residues, unreacted raw materials, and other residues. my country produces over 10 million tons of such solid wastes annually; therefore, the efficient treatment and disposal of these wastes has always been a hot topic of concern within the industry.

[0004] To improve the nickel recovery rate, this invention aims to recycle and utilize the solid waste generated from the industrial production of sodium sulfide. Summary of the Invention

[0005] To address the problem of recovering nickel from tailings of low-iron, high-magnesium laterite nickel ore, this invention provides a method for recovering nickel from tailings of low-iron, high-magnesium laterite nickel ore. This method aims to convert waste residue and solid waste generated during sodium sulfide production into useful additives for recovering nickel from tailings of low-iron, high-magnesium laterite nickel ore.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A method for recovering nickel from tailings of low-iron, high-magnesium laterite nickel ore includes the following steps:

[0008] Step 1, Raw material processing: The collected low-iron, high-magnesium laterite nickel ore tailings and solid waste are dried in a 105℃ drying oven for 24 hours. The dried material is crushed using a vibrating mill and mineral powder with a particle size of less than 75μm is collected using a 200-mesh sieve.

[0009] Step 2, Mixing: Weigh the tailings, additives, and reducing agent using an electronic balance, mix them evenly, and then evenly place the mixed sample into a high-temperature resistant corundum crucible.

[0010] Step 3, Reduction Roasting: Seal the corundum crucible filled with the ore sample and place it in a tube furnace. Pour in sufficient nitrogen gas to ensure that air is removed from the furnace. Start the instrument program and heat to the required temperature at a rate of 10℃ / min. Roast for the set time. After roasting, quench the roasted sample in water.

[0011] Step 4, Magnetic separation: Add deionized water to the roasted sample and wet grind it in a vibrating mill for 10 minutes, then rinse it clean. Dilute the wet-ground sample with water and separate the nickel-iron concentrate from other impurities using a tubular vibrating magnetic separator under a magnetic field strength of 1600 Oe.

[0012] Step 5, Sampling and Analysis: Calculate the nickel grade and nickel recovery rate of the completely dried nickel-iron concentrate product.

[0013] Furthermore, in step 2, the additive is sodium sulfide solid waste.

[0014] Furthermore, in step 3, the amount of tailings added is 200g, the amount of additives added is 25g~175g, and the amount of reducing agent added is 20g-50g.

[0015] Furthermore, in step 3, the calcination temperature is 1250℃~1400℃, and the reduction time is 1.5h~2.5h.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows.

[0017] 1. Comprehensive utilization of resources: This invention makes full use of the solid waste resources generated from the industrial production of sodium sulfide and transforms them into valuable additives. This not only reduces the cost of waste treatment and disposal, but also reduces the demand for fresh raw materials.

[0018] 2. Economic Benefits: By using sodium sulfide solid waste as an additive, this invention can achieve a nickel grade greater than 2.6% and a nickel recovery rate greater than 65% under optimal experimental conditions. This helps reduce the waste of nickel resources, improves the sustainable recycling and reuse of resources, and thus is more economically attractive. Attached Figure Description

[0019] Figure 1 Process flow diagram of this invention. Detailed Implementation

[0020] A method for recovering nickel from tailings of low-iron, high-magnesium laterite nickel ore includes the following steps:

[0021] Step 1, Raw material processing: The collected low-iron, high-magnesium laterite nickel ore tailings and solid waste are dried in a 105℃ drying oven for 24 hours. The dried material is crushed using a vibrating mill and mineral powder with a particle size of less than 75μm is collected using a 200-mesh sieve.

[0022] Step 2, Mixing: Weigh the tailings, additives, and reducing agent using an electronic balance, mix them evenly, and then evenly place the mixed sample into a high-temperature resistant corundum crucible.

[0023] Step 3, Reduction Roasting: Seal the corundum crucible filled with the ore sample and place it in a tube furnace. Pour in sufficient nitrogen gas to ensure that air is removed from the furnace. Start the instrument program and heat to the required temperature at a rate of 10℃ / min. Roast for the set time. After roasting, quench the roasted sample in water.

[0024] Step 4, Magnetic separation: Add deionized water to the roasted sample and wet grind it in a vibrating mill for 10 minutes, then rinse it clean. Dilute the wet-ground sample with water and separate the nickel-iron concentrate from other impurities using a tubular vibrating magnetic separator under a magnetic field strength of 1600 Oe.

[0025] Step 5, Sampling and Analysis: Calculate the nickel grade and nickel recovery rate of the completely dried nickel-iron concentrate product.

[0026] Furthermore, in step 2, the additive is sodium sulfide solid waste.

[0027] Furthermore, in step 3, the amount of tailings added is 200g, the amount of additives added is 25g~175g, and the amount of reducing agent added is 20g-50g.

[0028] Furthermore, in step 3, the calcination temperature is 1250℃~1400℃, and the reduction time is 1.5h~2.5h.

[0029] Example 1.

[0030] The tailings from the low-iron, high-magnesium laterite nickel ore obtained from the Dagong Mountain in Myanmar contain 0.23% nickel, 7.85% iron, 21.68% magnesium, 44.17% silicon, and 8.94% aluminum.

[0031] First, the tailings sample and solid waste were dried at 105℃ for 24 hours, crushed using a vibratory mill, and sieved through a 200-mesh sieve to obtain mineral powder with a particle size less than 75μm. Then, 200g of tailings sample, 60g of additives, and 20g of reducing agent were weighed and thoroughly mixed. The homogeneous mixture was placed in a high-temperature resistant corundum crucible and calcined in a tubular resistance furnace under sealed conditions, with sufficient nitrogen gas introduced to ensure air removal. The temperature was increased at a rate of 10℃ / min, reaching 1250℃, and held for 2.5 hours. The molten calcined ore was slowly poured into a water quenching tank and cooled to room temperature. Next, the sample was wet-milled for 10 minutes, rinsed clean, diluted with water, and then separated from other impurities using a tubular vibrating magnetic separator under a magnetic field strength of 1600 Oe.

[0032] The experimental results showed that the nickel grade was 3.02% and the recovery rate was 66.8%.

[0033] Example 2.

[0034] The tailings from a low-iron, high-magnesium laterite nickel ore mine obtained from Indonesia contain 0.64% nickel, 5.91% iron, 24.97% magnesium, 41.84% silicon, and 7.47% aluminum.

[0035] First, the tailings sample and solid waste were dried at 105℃ for 24 hours, crushed using a vibratory mill, and sieved through a 200-mesh sieve to obtain mineral powder with a particle size less than 75μm. Then, 200g of tailings sample, 70g of additives, and 30g of reducing agent were weighed and thoroughly mixed. The uniformly mixed sample was placed in a high-temperature resistant corundum crucible and calcined in a tubular resistance furnace under sealed conditions, with sufficient nitrogen gas introduced to ensure air removal. The heating rate was 10℃ / min, reaching 1300℃, and held for 2 hours. The molten calcined ore was slowly poured into a water quenching tank and cooled to room temperature. Next, the sample was wet-milled for 10 minutes, rinsed clean, diluted with water, and then separated from other impurities using a tubular vibrating magnetic separator under a magnetic field strength of 1600 Oe.

[0036] The experimental results showed that the nickel grade was 2.70% and the recovery rate was 68.7%.

[0037] Example 3.

[0038] The tailings from the low-iron, high-magnesium laterite nickel ore obtained from the Philippines contain 1.3% nickel, 6.29% iron, 23.48% magnesium, 43.89% silicon, and 6.68% aluminum.

[0039] First, the tailings sample and solid waste were dried at 105℃ for 24 hours, crushed using a vibratory mill, and sieved through a 200-mesh sieve to obtain mineral powder with a particle size less than 75μm. Then, 200g of tailings sample, 55g of additives, and 25g of reducing agent were weighed and thoroughly mixed. The uniformly mixed sample was placed in a high-temperature resistant corundum crucible and calcined in a tube furnace under sealed conditions, with sufficient nitrogen gas introduced to ensure air removal. The temperature was increased at a rate of 10℃ / min, reaching 1350℃, and held for 2 hours. The molten calcined ore was slowly poured into a water quenching tank and cooled to room temperature. Next, the sample was wet-milled for 10 minutes, rinsed clean, diluted with water, and then separated from other impurities using a tube vibrating magnetic separator under a magnetic field strength of 1600 Oe.

[0040] The experimental results showed that the nickel grade was 3.14% and the recovery rate was 73.6%.

[0041] The embodiments of the present invention have been disclosed and described in detail. However, it should be emphasized that relational terms such as "first" and "second" are used only to distinguish entities or operations and do not necessarily imply an actual relationship or order between them. Furthermore, the terms "comprising," "including," and variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus involving a list of elements includes not only the listed elements but also other elements not expressly listed, as well as elements inherent in the process, method, article, or apparatus.

[0042] Although embodiments of the present invention have been shown and described, it should be noted that these embodiments are merely exemplary and should not be considered as limiting the invention. Those skilled in the art can make various changes, modifications, substitutions, and alterations to the above embodiments without departing from the principles and spirit of the invention. Therefore, the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for recovering nickel from low-iron high-magnesium type laterite nickel ore tailings, characterized by, Comprising the following steps: Step 1, raw material treatment: the collected low-iron high-magnesium laterite nickel ore tailings and solid waste are dried in a 105℃ drying box for 24 hours, the low-iron high-magnesium laterite nickel ore tailings contain 0.23% nickel, 7.85% iron, 21.68% magnesium, 44.17% silicon and 8.94% aluminum; the dried material is crushed using a vibration mill sample machine, and a 200-mesh sieve is used to collect mineral powder with a particle size of less than 75μm; Step 2, ore mixing: use an electronic balance to weigh 200g of tailings sample, 60g of additive sodium sulfide solid waste, and 20g of reducing agent, mix evenly, and evenly put the mixed sample into a high-temperature-resistant corundum crucible; Step 3, reduction roasting: close the corundum crucible filled with ore sample, put it into a tube-type electric resistance furnace, and introduce sufficient nitrogen to ensure that the air in the furnace is exhausted; Start the instrument program, heat to 1250℃ at a temperature rising rate of 10℃ / min, keep for 2.5 hours, slowly pour the molten roasted sand into a water quenching pool, and cool to room temperature; Step 4, magnetic separation: add deionized water to the roasted sample, wet grind in a vibration mill sample machine for 10 minutes, and finally rinse clean; dilute the wet-ground sample with water, separate the nickel-iron concentrate from other impurities through a tubular oscillating magnetic separator under a magnetic field intensity of 1600Oe; Step 5, sample analysis: calculate the nickel grade and nickel recovery rate of the completely dried nickel-iron concentrate product.

2. A method for recovering nickel from low-iron high-magnesium type laterite nickel ore tailings, characterized by, Comprising the following steps: Step 1, raw material treatment: the collected low-iron high-magnesium laterite nickel ore tailings and solid waste are dried in a 105℃ drying box for 24 hours, the low-iron high-magnesium laterite nickel ore tailings contain 0.23% nickel, 7.85% iron, 21.68% magnesium, 44.17% silicon and 8.94% aluminum; the dried material is crushed using a vibration mill sample machine, and a 200-mesh sieve is used to collect mineral powder with a particle size of less than 75μm; Step 2, ore mixing: use an electronic balance to weigh 200g of tailings sample, 60g of additive sodium sulfide solid waste, and 20g of reducing agent, mix evenly, and evenly put the mixed sample into a high-temperature-resistant corundum crucible; Step 3, reduction roasting: close the corundum crucible filled with ore sample, put it into a tube-type electric resistance furnace, and introduce sufficient nitrogen to ensure that the air in the furnace is exhausted; Start the instrument program, heat to 1250℃ at a temperature rising rate of 10℃ / min, keep for 2.5 hours, slowly pour the molten roasted sand into a water quenching pool, and cool to room temperature; Step 4, magnetic separation: add deionized water to the roasted sample, wet grind in a vibration mill sample machine for 10 minutes, and finally rinse clean; dilute the wet-ground sample with water, separate the nickel-iron concentrate from other impurities through a tubular oscillating magnetic separator under a magnetic field intensity of 1600Oe; Step 5, sample analysis: calculate the nickel grade and nickel recovery rate of the completely dried nickel-iron concentrate product.

Images